Breast milk is not a substitute for vaccination.

By Helen Petousis Harris 02/07/2013

It is not uncommon to find folks promoting breastfeeding as a way to boost their children’s immune systems as an alternative rather than an adjunct to vaccination. On the West Coast, this philosophy is hindering the regions efforts in achieving high enough vaccine coverage to prevent disease as noted in the Herald this week.

When it comes to prevention of infectious diseases breastfeeding is certainly not a universal elixir.

It is well accepted that infants receive specific immunity in the form of antibodies from their mother through the placenta before birth and in breast milk if they are being breast fed against a range of infections. These antibodies are temporary and wane within weeks to months. Whether a baby receives any antibodies against a particular disease and whether these antibodies are actually protective are dependent on a range of variables. Here are two examples which are of particular concern to communities who do not vaccinate. The two most infectious diseases known to man.

Pertussis (whooping cough)

Unless a mother has been recently infected with pertussis or very recently vaccinated she will not pass antibody on to her infant either transplacentally or in breast milk. This is simply because she will have no circulating antibody herself to pass on.  The only way to protect baby is to vaccinate baby. Interesting study some years ago in region in Italy  where pertussis was endemic  in the absence of the use of vaccine. While breastfeeding appeared protective against acute lower respiratory infection, breast-fed infants had the same risk for hospitalisation with pertussis-like illness as bottle fed babies. Breastfeeding does not protect against pertussis. NZ currently has a pertussis epidemic. Pertussis can be lethal in young infants.


While infants may receive protective levels of antibody against measles from their mother, this rapidly wanes leaving them vulnerable. There is little or no measles antibody passed through breast milkA study in Belgium found even when mothers had experienced clinical  measles disease the antibodies passed to their babies only endured for a median of up to 3.78 months. Breastfeeding did not impact on the decay time of antibody. There is certainly some evidence that breastfeeding can reduce the severity of measles infection.  A large British study   investigated if breastfeeding modified clinical measles and also the effect of immunisation. Breastfeeding was associated with a modest reduction in measles diagnosis but in contrast measles vaccination was highly associated with a low risk for measles. In other words, breastfeeding helps a bit but vaccination is very effective.

Best of all – breastfeeding improves the immune response to some vaccines!

0 Responses to “Breast milk is not a substitute for vaccination.”

  • Surely you have this around the wrong way.

    Noun: A thing added to something else as a supplementary rather than an essential part.

    Adjective: Connected or added to something, typically in an auxiliary way: “alternative or adjunct therapies”.

    To imply that breastfeeding plays second fiddle to vaccination is an interesting concept for a front line well-child advocate.

  • One of the things I like about science is that you’re forever learning new things. I’d be interested to know how breastfeeding improves the immune response to some vaccines – ?

  • “To imply that breastfeeding plays second fiddle to vaccination is an interesting concept for a front line well-child advocate.”

    It isn’t to me. Breast feeding is good for mother and baby, human milk for human babies and while the infant is especially vulnerable it does give immunoglobulins that can give some protection from some illnesses, particularly diarrhoeal ones but others as well. A child also gets placental antibodies at the end of pregnancy.

    Fantastic, except to get specific, long lasting immunity, what must happen is the child needs to make their own disease-specific anti-bodies, that is why they are considered immunologically naive up until at least the age of six. Either they must contract the disease (and incur a high risk of complications) or be vaccinated to protect them (a strategy with a low risk).

    You don’t breastfeed forever and any passive immunity wanes fairly quickly, so whatever benefits a child might gain are temporary and limited in scope. It’s erroneous to say that it ‘boosts’ the immune system, breastfeeding is probably better described as supplementing or complementing it in the period where the child is developing it’s own immune system. So yes, breastfeeding is great and definitely does help a child get a good start in life, but isn’t a magic bullet that means a child is automatically protected from infectious disease. For instance, as pointed out in the OP, a baby isn’t protected by and large from whooping cough and if vaccination isn’t done the child is vulnerable through a time when they are at most risk from the disease. I’d also note whooping cough is pretty foul to contract at any stage.

    • Thanks Michelle, I agree. This leads onto Grant’s question too. Some of the goodies in breast milk have immunomodulating properties. Aside from immunoglobulins (antibody) there are a range of other bioactive compounds including cytokines and commensal bacteria. It is thought that some of these modulating factors may be responsible in some way for the better antibody response to polio, tetanus, diphtheria, Hib and pneumococcal vaccines (probably others) observed in breast fed babies compared to formula fed babies. A range of ideas of which particualr factors could play a role in this have been proposed but I am not sure if there is any direct evidence for a particular mechanism at this stage, just a lot of possibilities. Be interested to hear if anyone has knowledge of direct mechanisms. Helen.

  • Hi Ron – speaking as a child health advocate I agree that the word ‘adjunct’ in this particular context is entirely appropriate – breast feeding is supplementary support to vaccination as Helen describes with these vaccine preventable diseases – she correctly pointed out breast feeding for pertussis is probably of very limited usefulness, breast feeding is likely offer more protection for measles but time limited. Breast feeding offers passive protection, but the infant does not create any long term memory. This of course in no way denies the signficant range of many other very important aspects of breast feeding. A conversation about the science is more productive, than word play that pulls comments out of context. Nikki

  • Thanks, Helen – makes sense. (Off topic: I’m now left wondering how the bacteria get into breast milk and a bunch of related things!)

    • The mind boggles! 🙂 Although in all seriousness it is truly a fascinating question. Apparently there are many hundreds of bacterial species in breast milk. Some keen people in Spain identified them and found over 700 including strep and staph. They also posed the question around some bacteria entering from the baby’s mouth and entering the breast milk that way. Obese mothers had less bacteria than healthy weight mothers – interesting when you note the association between obese mothers and the development of atopy in the baby. Vaginal birth resulted in more and greater diversity of bacteria. Maybe Siouxsie knows?

  • I may be wrong (& certainly not an expert!), but was told when I had kids, that breastmilk itself has very few bacteria, but the baby picks it up from the mothers skin. Apparently, a generation or so ago, women were told they should wash their nipples before breastfeeding, but now it is acknowledged that those bacteria can have beneficial effects. I expect by virtue of the environment it would be only select types of bacteria though.

    Very interesting & enjoyable blog, and from my perspective, if an adult immune system is not able to fight off many off these nasty vaccine preventable diseases, it’s hard to see how breastmilk can do any better. This is not to undermine breastfeeding in any way, but the benefits of vaccination seem quite clear in the reduction of diseases previously prevalent, especially in eras where formula feeding was never an option.

    • Yes, isn’t it funny how we were told that breast milk was sterile and it turns out to be more like yoghurt. I have always been a fan of the hygiene hypothesis, at first it appealed to my disinclination to clean everything. The fact that exposure to microbes is essential for the development of a healthy immune system is even more appealing as it conforms to everything we know about immunity and evolution. The experiments where researchers infected themselves with parasites by drinking cocktails of pin worms and cleared up their asthma because the IgE had the parasites to attend to instead of going around getting mast cells to release histamine are a case in point – now I think I too digress!!